GB2215638A

GB2215638A - Method and means for fire retardation

Info

Publication number: GB2215638A
Application number: GB8806773A
Authority: GB
Inventors: Frederick Charles Coles
Original assignee: GRAFOCHEM Ltd
Current assignee: GRAFOCHEM Ltd
Priority date: 1988-03-22
Filing date: 1988-03-22
Publication date: 1989-09-27
Anticipated expiration: 2008-03-22
Also published as: GB8806773D0; GB2215638B

Abstract

A method of effecting fire retardation on the interiors of buildings is practised by the adhesion to the surface where fire is to be retarded of tiles, for example, made of aluminium foil (12) having one surface thereof a layer of intumescent paint (14) applied under controlled conditions to ensure that said layer has a uniform prescribed thickness. <IMAGE>

Description

Method and Means for Fire Retardation This invention relates to a method of and means for effecting fire retardation, more particularly on the interiors of building structures of all kinds, ranging from domestic, industrial, commercial, agricultural and military buildings and ancillary buildings such as greenhouses, stores, warehouses and barns to vehicular structures such as goods vehicles, caravans, ships and boats. The term "building structure" s tc be inter -- e-. eccc-d-nch .

It is known that fire retardation can be introduced into buildings by the application, to relev r, ar.s appropriate parts of building structures, for example roofs, ceilings, doors, partitioning or the like, by the application of a surface layer of intumescent paint.

Intumescent paint contains additives which cause the layer of paint to swell in the presence of strong heat and high temperatures which occur during progress of. fire. Although the paint layer may become charred and blackened, it maintains its integrity for a period of time which is in part dependent on the thickness of the layer. The swelling which occurs during this period enables the paint layer to absorb a substantial amount of air, which under these conditions acts as a thermal insulant, reducing the amount of heat reaching the part of the building structure underneath, thus slowing down its rise in temperature and thereby slowing down spread of the fire.

Intumescent paint is generally not suitable for application by brush, and is usually applied by spraying. However, it is only effective to retard a fire for any given period, in accordance with British Standards, if all points of the area to be protected are covered by a thickness of paint not less than a specific minimum thickness corresponding to the given period for which fire retardation is intended.

However, spraying the intumescent paint on site has such difficulties of control that two applications of paint are invariably necessary to ensure that the thickness of the final protective layer is at no point less than the specified minimum thickness. Moreover, spraying with intumescent paint requires the skilled use of specialist spraying equipment and therefore the paint has to be applied by skilled operators, making the work expensive and often inconvenient.

According to one aspect of the present invention, there is provided a method of effecting fire retardation on the interiors of buildings, according to which any part at which spread of fire is to be retarded has adhered to the surface thereof an element of sheet material which on the face thereof opposite the adhered face bears a layer of intumescent paint previously applied under controlled conditions such that the layer of paint has a substantially uniform prescribed thickness.

According to another aspect of the invention, there is provided an element of sheet-material for adhering to an interior building part at which spread of fire is to be retarded, said element bearing on one face a layer of intumescent paint of substantially uniform prescribed thickness.

The intumescent paint employed in practising the invention may be any commercially available intumescent paint, but is preferably an intumescent paint which has high adherence to the sheet material which carries it, and retains this high adherence when the paint swells in the presence of strong heat. A preferred paint may incorporate a fungicide, and possibly one or more additives which assist in reducing moisture condensation. The paint layer on the-sheet elements adhered to the relevant parts of the building, although not a good thermal insulant until the layer swells in the presence of strong heat, may thus serve useful purposes, in addition to decorative purposes, even though it may never be called upon for the purpose of fire retardation.

A preferred layer may have any specified uniform thickness fror; say 1 m up to 5 m, depending on the given perioc for which fire retardation is intended. For example, a paint treated sheet element in the form of a panel adhered to the face or to each face of a door, may give fire retardation nominally for thirty minutes, in either one or both directions, if the paint layer has a uniform thickness of 1 mm, and fire retardation nominally for one hour if the paint layer has 2 mm thickness. Typically, in the event of a fire, a 1 mm intumescent paint thickness may swell to a thickness of up to 4 mm, thereby developing a high porosity which allows absorption of a 4 mm thickness of air for acting as a thermal insulant.

A preferred base sheet material is aluminium foil, for example in the form of strips, tiles or panels, although other sheet metallic material, plastics sheet material or a material such as fibre board may alternatively be employed.

Aluminium foil is an example of a preferred sheet material which is semi-flexible and which can thus be conformed to the possibly non-flat surface of the building part to which it is to be adhered. However, the fire-retardant element in accordance with the invention can be cut to size for adherence to angular surfaces. A preferred intumescent paint is one which is also capable of flexing, with the semi-flexible strip, tile or panel to which it is applied, without cracking or otherwise creating discontinuities therein.

The aluminium foil in the form of a large sheet may be sprayed with an etching primer and dried before application, again by spraying, of the intumescent paint. The paint covered sheet may then be dried before guillotining to a required strip, tile or panel size. In contrast with spraying on site, the intumescent paint layer is sprayed on to the aluminium foil (or other sheet material) under factory conditions, whereby the spraying process can be tightly controlled and it can be ensured that the sprayed layer has a specified uniform thickness. Usually, the complete thickness of paint specified in any particular case can be applied in a single spraying step.

The aluminium foil or other sheet material bearing the fire-retardation layer may, on the face to be adhered to the building part, be provided with a self-adhesive layer protected by a peel-off skin. À preferred adhesive is one which maintains good adhesion in the presence of heat, although it will be appreciated that, in the event of a fire, the underlying sheet material and adhesive are shielded by the swelled layer of intumescent paint which is exposed to the fire.

The exposed surface of the fire-retardation layer may be textured, so that, on swelling, a maximised surface area is exposed for absorption of air. The textured surface, also taking into account the possibility of incorporating colouring pigment into the paint, imparts a pleasing and attractive finish to the building parts to which firetardation strips, tiles or panels are adhered.

The method and means in accordance with the invention is exemplified in the following description, making reference to the accompanying drawing, in which - the single figure shows a fire retardation panel.

Refe-ri^^ te the drair, the illustrated fire-retardstio tile 10 comprises an element 12 of aluminium foil, say of the order of 0.2 mm thick, having applied to one face thereof a layer 14 of intumescent paint having a uniform thickness of 1 mm in order to give fire retardation for a specified nominal period. The layer 14 of intumescent paint is applied under factory conditions by a tightly controlled spraying process which ensures that the layer is of uniform thickness throughout. The paint layer is preferably given a textured surface 16.

In practice, a large sheet, e.g. a roll, of aluminium.foil is sprayed with the intumescent paint, and the large sheet is subsequently guillotined into tiles of a required shape and size.

An adhesive layer 18 is preferably applied to the other face of the aluminium foil, protected by a peel-off paper or like covering sheet 20. In-this case, the tile in accordance with the invention is preferably manufactured from a starting material consisting of adhesive-coated rolled aluminium foil. This foil is progressively unrolled and held taut across a rigid board, possibly being unrolled, zig-zag fashion, across a number of boards which are stacked, the foil being cut at the ends to allow de-stacking.

The foil held taut on a board is then etched with a primer, dried, and has the intumescent paint layer applied by the tightly controlled spraying process. The foil is guillotined after the paint has dried.

The fire-retardant element in accordance with the invention may be employed on a DIY basis, and may be used on any building parts where fire-retardation is required, including industrial, commercial and domestic premises, and also boat interiors or to like. z typical t' le rca f uc- DIY basis may be about 30 cm by 30 cm, but smaller or larger tiles or strips may be preferred for adherence to shaped building parts such as beamed ceilings. In the case of a door to be protected, the use of a single fireretardant panel cut specially to size is generally to be preferred.

Various modifications of the above-described and illustrated fire-retardant element are possible within the scope of the invention hereinbefore defined.

Claims

1. A method of effecting fire reardation on the interiors of buildings, according to which any part at which spread of fire is to be retarded has adhered to the surface thereof an element of sheet material which on the face thereof opposite the adhered face bears a layer of intumescent paint previously applied under controlled conditions such that the layer of paint has a substantially uniform prescribed thickness.

2. Fire retardation means for carrying out the method of claim 1, comprising an element of sheet material for adhering to an interior building part at which spread of fire is to be retarded, said element bearing on one face a layer of intumescent paint of substantiaily uniform prescribed thickness.

3. Fire retardation means according to claim 2, wherein the intumescent paint is one which has a high adherence to the sheet material which carries it, and retains this high adherence when the paint swells in the presence of strong heat.

4. Fire retardation means according to claim 2 or claim 3, wherein the paint incorporates a fungicide.

5. Fire retardation means according to claim 2 or claim 3 or claim 4, wherein the paint incorporates one or more additives for reducing moisture condensation.

6. Fire retardation means according to any of claims 2 to 5, wherein the paint layer is of a uniform thickness in the range 1 to 5 mm.

7. Fire retardation means according to any of claims 2 to 6, wherein the sheet material is aluminium foil.

8. Fire retardation means according to any of claims 2 to 6, wherein the sheet material is in the form of a strip, tile or panel thereof of predetermined size.

9. Fire retardation means according to any of claims 2 to 8, hexing a self-adhesive layer protected by a peel-off skin on the side opposite to the layer of intureccert pa-

10. Fire retardation means according te claim a, rein the adhesive is one which retains its adhesive properties in the presence of heat.

11. Fire retardation means according to any of claims 2 to 10, wherein the exposed surface of the layer of intumescent paint is textured.

12. Fire retardation means according to any of claims 2 to 11, wherein the paint incorporates a colouring pigment.

13. A method of producing the fire retardation means of claim 8 or any claim appendant thereto, wherein a large aluminium foil sheet is sprayed with an etching primer prior to application of the layer of intumescent paint of.

prescribed uniform thickness, and dried before guillotining into strips, panels or tiles of predetermined size.

14. A method of fire retardation as claimed in claim 1 and substantially as hereinbefore described.

15. Fire retardation means substantially as hereinbefore described with reference to the accompanying drawings.